Many people have difficulty properly focusing their eyes on near objects and especially focusing on an object within reading distance. It is frustrating to be working simultaneously on a project that requires near and distance vision or near and mid-range vision because differential focal lengths are involved, and this usually requires different lenses for proper focusing of eyes needing correction.
Moreover, where bifocal eyeglasses are worn, it is customary for the close or reading lens to be located in the lower part of the glasses while the more distant vision lens is in the upper part of the lens body of the eye glasses. This is a disadvantage for many commercial users, such as mechanics who must look up towards a mechanism, or for airplane pilots who must look overhead at very close instruments and down for more distant instruments and then look out of the airplane for scrutinizing air traffic or ground activity.
It would be desirable to have made available eye glasses having multi-focal lenses than can be rotated to bring an appropriate power lens into use. Such an apparatus is the subject of the present invention.